Glucose absorption from peritoneal dialysate is associated with a gain in fat mass and a reduction in lean body mass in prevalent peritoneal dialysis patients

The majority of peritoneal dialysates use glucose to generate an osmotic gradient for the convective removal of water and Na. Although glucose can potentially be absorbed, previous studies have failed to establish whether this leads to increased fat weight gain. We measured body composition using bioimpedance in peritoneal dialysis (PD) patients, electively starting PD, attending for their first assessment of peritoneal membrane function after 2-3 months, and then after 12 months. We studied 143 patients: eighty-nine (62.2 %) males, fifty-three (37.1 %) diabetics, mean age 61.3 (SD 14.9) years, with ninety (62.1 %) patients treated by automated PD cyclers with a daytime icodextrin exchange and thirty-seven (25.9 %) by continuous ambulatory PD. Median fat mass increased by 1.8 (-0.5 to 4.1) kg, whereas fat-free mass fell -1.3 (-2.9 to 1.0) kg, and the increase in fat mass was negatively associated with the fall in soft lean mass (r -0.41, P < 0.001). Increased fat mass was associated with measured peritoneal glucose absorption (r 0.69, P < 0.001), and glucose absorption was associated with the amount of 22.7 g/l glucose dialysate (OR 2.0, 95 % CI 1.5, 2.5, P < 0.001), peritoneal urea clearance (OR 9.5, 95 % CI 2.4, 37.1, P = 0.001) and male sex (OR 4.8, 95 % CI 1.5, 14.9, P = 0.008). We report an observational study in prevalent PD patients following body composition from their first assessment of PD membrane function for approximately 12 months, and despite the majority of patients prescribed icodextrin, we have demonstrated not only an association between intra-peritoneal glucose absorption and fat weight gain but also loss of fat-free mass.